Idle wheel bearing



March 11, 1958 F/MEYER IDLE WHEEL BEARING 2 Sheets-Sheet 1 Filed June 30, 1953 m K Wm m H K m w a MN N F. MEYER IDLE WHEEL BEARING March 11, 1958 2 Sheets-Sheet 2 Filed June 30, 1953 mm E mm m w 0 1 F a m m X 4 3 p w 9 I... 0 MW who ./I\5 N 1| 8 w P 5 z 3 4 8 MW 9 W, 9 7 M "w r tit ed 2,826,036 Patented Mar. 11, 1958 IDLE WHEEL BEARING Friedrich Meyer, Grenchen, Switzerland, assignor to Felsa S. A.., Grenchen, Switzerland, 21 joint stock com- P y Application lane 36', 1953, Serial No. 3653M iairns priority, application Switzerland November 16, 12 52 4- Claims. (CL 74-421) This invention relates to idle wheel bearings, particularly to bearings for very thin idle wheels in watches.

idle wheels are used in self-winding watches wound up by the displacements of a roclcable weight in both directions. In this case said idle Wheels are often combined with a one way engaging clutch, thus constituting a freewheel mechanism.

in prior art such wheels are merely journaled on an axle by an internal seat provided on said wheels.

in watches of very small size the diameter of said wheels should not be reduced as such as the dimension of the watch, but the thickness of the wheels must be reduced, so that the seat of these wheels becomes very small and it may no longer ensure the wheel to always stay normal to its axle.

't is therefore an object of the invention to provide satisfactory bearing conditions for idle wheels by providing abutments on the frame in which said wheels are mounted, said abutments being adapted for cooperating with the peripheral portion of the wheel.

Another object of the invention is to avoid too much friction between said wheel and said abutments.

Still further objects of the invention will appear from the following description.

One embodiment of the invention is shown diagrammatically by way of example in the drawings affixed to this specification and forming part thereof.

in the drawings:

Fig. i is a plan view of the frame of a self-winding mechanism set in place on a watch movement;

Fig. 2 is a cross-sectional view of the self-winding mechanism along line ll-ll of Fig. 1;

Fig. 3 is a part-sectional view of the frame of the watch along line llllll of Fig. 1;

Fig. 4- is a view similar to that of Fig. 2 but to an enlarged scale; and i Fig. 4a shows a detail of Fig. 4 to even a larger scale.

The self-winding watch represented in the drawings has particularly been designed as a ladys watch of very small size, the width of the movement being about 0.4 inch.

Fig. 1 shows a frame for the self-winding mechanism of a watch, and this frame is fixed on the watch movement frame. The self-winding mechanism frame consists of a substantially rectangular base-plate 22 and a bridge 23 shown by dot-dash lines in Fig. l. Base-plate 22 has the same width as the watch movement frame but it is longer than the latter.

Two deep cylindrical recesses 24, 25 of substantially the same diameter are provided in base-plate 22. The axes of said recesses lie in the plane defined by the major axis of symmetry of base-plate 22. They are symmetrically arranged on each side of the center of said base-plate. Recess 25 comprises two undercut portions 26 (clearly shown in Fig. 3), which define two overhanging portions 27 of base-plate 22. Two shallow part-cylindrical recesses 28, 29 are further provided in base-plate 22, concentrically to its center (see also Fig. 2). In boring recess 29 two part-circular ribs 30 of rectangular cross-section (Figs. 1, 2 and 4) are provided at the bottom of said recess. A passage 31 of the same depth as recesses 24 and 25 sets said recesses into communication with one another.

The base-plate 22 is secured to the watch movement frame by a cylindrical steady pin 32 by three screws 35, 36 and 37 with conical heads.

A steady pin 4t is set into an adequate hole of the unrecessed portion at the left of base-plate 22 in- Fig. 1,. and two further similar steady pins 41 are set in adequate holes of overhanging portions 27, as shown in particular in Fig. 3. Three tapped bores 42 are provided each in the vicinity of one of said steady pins and 41. These three pins protrude from the upper surface of base-plate 22, each to the same extent which almost corresponds to the thickness of bridge 23. The latter is laterally positioned, with respect to base-plate 22, by said pins 4% and 41 fitting adequate holes provided in bridge 23. Bridge 23 is axially fixed to said base-plate by means of three screws screwed into holes 42.

Two wheels 52 and 53 pivot freely about a shaft or axle 5d pivoted itself in the center of the self-winding mechanism frame. They are alternately driven in the same direction by means of weights and gears (not shown), but they always rotate in opposite directions. Clutch mechanisms are so arranged between each wheel 52, 53 and axle 54 that said wheels drive axle 54 when rotating in a determined direction, whereas they are free from axle 54 when rotating in the other direction.

Axle also carries a pinion 58 meshing with a ratchet Pinion 58 is located within a circular hole 59 provided in the lower surface of base-plate 22.

Both similar clutch mechanisms provided between the two wheels :32, 53 and axle 54 are located each within circular indentations 60, 61 concentrically provided in said wheels. Each of these mechanisms comprises a stabilizing plate 62, 63 fixed to axle S4, and a wedging member 64, 65. Said stabilizing plates keep each of the wheels 52, 53 normal to axle 54, thus preventing said Wheels from clamping with axle 54-. Stabilizing plates 62, 63 also generally avoid that wheels 52, 53 gets inclined with respect to axle 54, which could easily occur (because of the very narrow seats of said wheels on said axle) and cause a rapid wear of said seats.

Collapsing in an upward direction, perpendicular to wheel 52, ofwedging member 64 and stabilizing plate 62, when said member is in clamping position, is prevented by bevelling both wall 81 of indentation 69 internally, and the upper edge 82 of the outer portion 59 of member 64 in a corresponding manner, as clearly shown in Fig. 4a. These bevelled portions also secure member 64 within indentation 60, when said member has once been set in place.

As previously mentioned, wheel 53 is also provided with a clutch mechanism consisting of a stabilizing plate 63, a wedging member and a spring 83, which are altogether located within a circular indentation 61 of said wheel. Elements 63, 65 and 83 are shaped like the corresponding elements of wheel 52 and the operation of this second clutch mechanism is the same as that of the first.

When any of the wedging members described before is in clamping position, wheels 52 and/or 53, on the one hand, and stabilizing plates 62 and/or 63, on the other hand, exert a shearing action on the axle on which said wheels pivot and said plates are fixed, respectively.

in order that this axle may hold out said shearing action without any risk of breakage, its diameter must have a sufiicient size in the portion on which said plates are fixed and said wheels pivot.

Since pinion 58 (made best integral with axle 54),

asaaoee is provided on a bracket portion of axle 54 (i. e. on a portion outwards both upper and lower bearings of axle 54), said axle cannot be formed integral with a portion of sufiicient diameter for pivoting wheels 52, and fixing plates 62, 63, because such an axle could not be set in place.

Therefore, axle 54 is machined with a lower small portion in which the teeth of pinion 53 are milled (Fig. 4), a truncated conical center portion 91'}, an upper cylindrical portion 91 and a pivot 92 at its top extremity.

The cone of center portion 90, having a very small apex angle, is open downwards and its diameter adjacent pinion 58 is smaller than that of said pinion, whereas its diameter adjacent said portion 91 is larger than that of said cylindrical portion.

The teeth of pinion 58 are milled throughout the truncated conical portion 99 (Fig. 4) at a depth which is substantially flush with portion 91.

The structure described of axle 54 allows a collar 93 to be easily passed through portion 91 and pressed along portion 99 until it abuts against pinion 53 as shown in the drawing. The shallow teeth milled in portion 9'8 firmly grip collar 93 and prevent any angular displacement thereof respective to axle 54.

Collar 93, which has a diameter larger than that of the circle defined by the tops of the teeth of pinion 58, acts as lower pivot of axle 54 and is accordingly supported in bearing engagement within a jewel 94 set in opening 59 of frame 22.

A hub member 95 is then pressed onto portion 91 of axle 54 until it abuts against the upper flange of the teeth milled throughout portion 90. Said member 95, shown in detail in Fig. 4, is formed with several outer stepped portions. A first lower flange 96 serves as axial abutment for wheel 53 which freely rotates around bearing surface 97 of hub 95. Said bearing surface 97 is somewhat wider than the thickness of the bottom of wheel 53, thus wheel 53 being given a small amount of play in axial direction between flange 96 and stabilizing plate 63 which is riveted at 98 to hub 95 on a portion 99 thereof. The width of portion 99 is equal to the thickness of stabilizing plate 63.

Surface 97 and portion 98 have together a width equal to the thickest outer portion of wheel 53 located beyond member 64. The diameter of portion 99 is smaller than that of surface 97 in order that wheel 53 may first be set in place and then plate 63 riveted to hub 95.

Wheel 52 is set in place after plate 63 has been riveted. and it rotates freely around a bearing surface 19- of hub 95, the diameter of said surface being still smaller than that of portion 99 and its width being somewhat larger than the thickness of the bottom of wheel 52. Due to the sizes of surface 1%, wheel 52 is also given a small amount of play in axial direction between plates 63 and es, the latter being riveted at 101 to hub 95, on a portion 102 thereof. The width of portion 192 corresponds to the thickness of plate 62. Surface 199 and portion 192 have together (like surface 97 and portion 99), a width equal to the thickest outer portion of wheel 52 located beyond member 64.

Hub 95 has still a center portion 193 extending somewhat beyond the upper flange of portion 102, in order to prevent said flange from contacting either bridge 23 or pierced jewel 1 34 which is set in bridge 23 and in which pivot 92 is held in bearing engagement.

Although the lower bearing of axle 54- is constituted by a surface of collar 93, Which has a diameter rather large, the friction between said collar and bearing jewel 94 does not disturb winding the watch too much, because axle 54 only rotates slowly.

When axle 54 together with collar 93, hub member 95 and both wheels 52, 53, has once been set in place and bridge 23 screwed onto base-plate 22, said axle is prevented from dropping downwards in the position shown in Fig. 4 by Wheel 53 which lies on part-circular ribs 39..

tit

i Fig. 4 shows the relative positions of the elements carried by axle 54 when the latter is vertical with pinion 53 downwards. Wheel 52 lies on wheel 53 which is cham' red at in order to reduce friction between both Wheels. Flates 62 and 63 lie on the bottom of indentations 6G and 61 of wheels 52 and 53, respectively.

in this position of axle 54, wheels 52 and 53 are kept perpendicular to said axle by ribs 39 as Well as by plates 62 and 63.

if the watch is then turned through an angle of 130 about a horizontal axis, axle 54 having a certain amount of play in axial direction together with the elements carried by it, drops upwards in Fig. 4 until either center portion 193 of hub contacts jewel re t, or wheel 52, which is also chamfered at 1%, lies on bridge 23 by its portion, or both portion M3 and wheel 52 contact each the corresponding parts of bridge 23. In said reversed position wheels 52 and 53 are again held substantially perpendicular to axle 5 by plates 62 and 63 and bridge 23.

if the watch is in such a position that axle 54 is substantially horizontal, wheels 52 and 53 are still in contact with one another because of the sizes of the several portions of hub 95 and they still are held substantially perpendicular to axle 54 by stabilizing plates 62, -63 which almost always contact the bottoms of indentations 6t} and 63, because of an oil film provided between the con tasting surfaces of said plates and the bottoms of the corresponding wheels, said oil film ensuring adhesion between each of said plates and the corresponding wheel.

Even without such an oil film at all, the wheels may lea e the stabilizing plates, but they are still held substantially perpendicular to axle 54 by ribs 39 and the lower Sli. race of bridge 23.

This bridge could, of course, also be provided, at its lower surface, with a rib analogous to ribs 36, the distance of the lower surface of said bridge and base-plate 2;; being increased accordingly.

it will be observed that there is no force in axial direction, which is applied to axle 54, but the own weights of he parts connected to said axle.

Various changes may be made in the configuration and arrangement of the parts hereabove described and shown in the drawings without departing from or sacrificing the advantages thereof.

I claim:

1. In an idle wheel arrangement, in combination, frame means including a pair of frame portions spaced from each other by a predetermined distance; a shaft carried by said frame 1 ans, said frame means supporting said shaft for rotation about its axis and for limited displacement; annular wheel means surrounding sai shaft, being coaxial therewith, extending into the space between said frame portions, and having a thickness which is less than said distance so that said frame portions limit axial movement of said Wheel means with respect to said shaft; pivot means fixed to said shaft at the portion thereof surrounded by said wheel means and supporting the latter for free turning movement about said shaft and for limited axial displacement with respect to said shaft; and limiting means carried by at least one of said frame portions for li mg the area of contact between said one frame portion and Wheel means.

2. In an idle Wheel arrangement, in combination, frame means including a pair of frame portions spaced from each other by a predetermined distance; a shaft carried by said frame means, said frame means supporting said shaft for rotation about its axis and for limited axial displacement; annular wheel means surrounding said shaft, being coaxial therewith, extending into the space between said frame portions, and having a thickness which is less than said distance so that said frame portions limit axial movement of said wheel means with respect to said shaft; and pivot means fixed to said shaft at the portion thereof surrounded by said wheel means and supporting the latter for free turning movement about said shaft and for limited axial displacement with respect to said shaft, said wheel means having a side surface area directed toward a surface area of one of said frame portions and one of said surface areas being raised to limit the contact area between said wheel means and said one frame portion.

3. In an idle wheel arrangement, in combination, a shaft; a hub member fixed to said shaft and having an outwardly extending annular flange coaxial with said shaft, said hub member having an outer face coaxial with said shaft; a pair of plates normal to the axis of said shaft fixed to and extending radially from said hub member, one of said plates being located between and spaced from the other of said plates and said flange; a pair of gears freely turnable on said outer face of said hub member for free rotational movement with respect to said shaft, one of said gears being located between said one plate and said flange and having between said one plate and flange a thickness slightly less than the distance between said one plate and flange so that said one gear has a limited axial play with respect to said shaft, and the other of said gears being located between said pair of plates and having between the latter a thickness slightly less than the distance between said plates so that said other gear also has a limited axial play between said plates, said pair of gears extending radially beyond said plates; frame means supporting said shaft for rotation about its axis and for limited axial displacement, said frame means having a pair of frame portions between which said pair of gears are located with slight clearance so that said pair of gears are axially movable to a limited extent between said frame portions; and limiting means located between said frame means and gears for limiting the area of contact between said frame portions and gears to a small fraction of the area of said gears.

4. In an idle wheel arrangement, in combination, a shaft; a hub member fixed to said shaft and having an outer, annularly stepped face coaxial with said shaft and forming a series of annular surfaces respectively located in planes normal to said shaft and each having a diameter greater than that of the preceding annular surface, said outer face of said hub member also forming a plurality of cylindrical surfaces respectively located between said annular surfaces and each having a diameter greater than that of the preceding cylindrical surface; a pair of plates respectively located in planes normal to said shaft and respectively being fixed to a pair of said cylindrical surfaces, a third one of said cylindrical surfaces extending between said plates and having an axial length equal to the distance between said plates and a fourth one of said cylindrical surfaces being located outside of the space between said plates next to the plate fixed to that one of said pair of cylindrical surfaces which is of a larger diameter than said third cylindrical surface; a first gear freely turnable on said fourth cylindrical surface and having a thickness between the plate next to said fourth cylindrical surface and the annular surface adjoining said fourth cylindrical surface and extending radially outwardly from the same a thickness slightly less than the distance between the latter annular surface and the latter plate, so that said first gear has a limited axial play with respect to said shaft, said first gear extending radially beyond said plates and having at a side surface directed toward said plates an annular projection defining a recess in which the plate next to said fourth cylindrical surface is located; a second gear extending between said plates and being freely turnable on said third cylindrical surface, said second gear having a thickness between said plates slightly less than the distance between said plates so that said second gear has a limited axial play with respect to said shaft, said annular projection of said first gear engaging said second gear when said first and second gears respectively engage said plates, and said second gear also having an annular projection defining a recess in which the plate fixed to the smaller of said pair of cylindrical surfaces is located; frame means supporting said shaft for rotation about its axis and for limited axial displacement and having a pair of spaced frame portions between which said pair of gears extend with slight clearance, one of said frame portions being located adjacent said first gear and having an arcuate rib directed toward the same for limiting the area of contact between said first gear and said one frame portion, the other of said frame portions being located adjacent the second gear and the annular projection of said second gear serving to limit the area of contact between said other frame portion and second gear.

References Cited in the file of this patent UNITED STATES PATENTS 2,088,098 Susor July 27, 1937 2,149,014 Fritzsch Feb. 28, 1939 2,645,895 Dubois July 21, 1953 

